Sports enthusiasts may desire to improve their performance through repeated practice. For example, a golfer may hit golf balls on a driving range and/or into a net. The golfer may want to assess each shot to fine-tune performance. A launch monitor can be used to assess performance by measuring one or more properties of the golf ball when it is struck. For example, the launch monitor can be used to measure a speed or launch angle of the golf ball when it is struck. However, conventional launch monitors tend to be expensive or inaccurate.